1. Technical Field
The present invention relates to a printing apparatus.
2. Related Art
A printing apparatus (for example, an ink jet printer) includes various motors such as a carriage motor for moving a carriage in which a printing head is mounted, or a transport motor for transporting a medium (for example, sheet). In addition, a control unit of the printing apparatus drives the motors based on a predetermined speed profile.
For example, in the case of the carriage motor, the control unit drives the carriage motor with acceleration, a constant-speed, and deceleration whenever the carriage is reciprocated in the width direction of the medium. Then, when reciprocating the carriage motor, in some cases, the speed of the carriage cannot be controlled to a target speed due to paper jams, or the like. Therefore, a technology of estimating an obstruction to the carriage movement from the carriage speed and if it is determined that the carriage movement is abnormal, stopping the scanning of the carriage is suggested (JP-A-2007-283561).
As described above, when driving the motor with acceleration, a constant-speed, and deceleration, since the driving of the motor is stable in the constant-speed range, there is a low possibility that an abnormality may be false-detected. However, in the constant-speed range, energy is great and the distance (a movement distance) is long. Therefore, there is a concern that influence due to an abnormality (damage to the sheet or failure of the movement mechanism, and the like) may be great if an abnormality occurs.
On the other hand, in an acceleration range or a deceleration range, the driving operation of the motor is unstable. Therefore, there is a high possibility that an abnormality may be false-detected. However, in the acceleration range or the deceleration range, the energy is small and the distance (the movement distance) is short. Therefore, the influence is small even though an abnormality occurs.
Therefore, if the determination of the speed abnormality is performed by same determination reference, there is a concern that the measures may be not performed appropriately when an abnormality occurs.